This proposal, as part of the Center theme to translate scientific findings to guide the development of resources and tools for parents, is aimed at parents with a teenager who is already starting to use drugs. The proposed research will test a new, innovative version of a brief intervention. This program will be home based rather than implemented by a counselor in a clinical setting. Consistent with the Center translational strategy, this proposed study is stage I to stage II research. The stage I activities will involve manual development, parent training development, and a small feasibility study; Stage II involves a formal efficacy randomized controlled trial. Subsequent to the efficacy trial, additional translational work by the Center's Communications Unit (Parent Advisory Board and the Partnership for a Drug Free America) will promote the product's transportability into the community. The study's potential to develop a user-friendly and scientifically sound parent intervention program benefits from being part ofthe proposed Center. The study's specific aims are the following: Aim 1. Design a new, parent-led and home based brief intervention to address mild-to-moderate drug abuse in the teenage child (age range 12-15). Aim 2. Evaluate the efficacy of the parent intervenfion using a random controlled trial. Two samples, 110 families each, will participate in the randomized controlled trial. Families will be randomly assigned to either an intervention or control conditions. Data to quantify intervention effects will be obtained by interviewing adolescents and target parent at multiple time points (baseline and 1-, 3-, 6- and 12-months post baseline). We hypothesize that the home based intervention will be superior to a control condition. Aim 3. To examine hypothesized mediating mechanisms that contribute to post-intervention drug use behaviors in the adolescent. Response to the intervention by the adolescent will be mediated by motivation, cognitions, problem solving, peer drug use, parenting skills and parent self-efficacy.